class_docstr: Represent an enumerated collection of values.
  
  .. note::
      Instances of ``Enumeration`` typically should not be constructed
      directly. Instead, use the |enumeration| function.
code: def __len__(self) -> int:
      return len(self._values)
  
file_path: bokeh/src/bokeh/core/enums.py
imports: from __future__ import annotations
  import logging
  from typing import Any, Iterator, Literal, get_args
  from ..None import colors, palettes
  from ..util.strings import nice_join
label_desc: Use image node_id 4 for calling the Enumeration obj's underlying member method code with example usage: obj.__len__() and returns: len